Introduce {next,previous}PositionOf() as replacement of {next,previous}() member functions in Positi

Source/core/editing/PositionTest.cpp

 // Copyright 2015 The Chromium Authors. All rights reserved.
 // Use of this source code is governed by a BSD-style license that can be
 // found in the LICENSE file.
 
 #include "config.h"
 #include "core/editing/Position.h"
 
 #include "core/editing/EditingTestBase.h"
 
 namespace blink {
 
 class PositionTest : public EditingTestBase {
 };
 
 TEST_F(PositionTest, downstreamAfterAnchor)
 {
     const char* bodyContent = "<p id='host'><b id='one'>1</b></p><b id='two'>22</b>";
     const char* shadowContent = "<b id='two'>22</b><content select=#one></content><b id='three'>333</b>";
     setBodyContent(bodyContent);
     setShadowContent(shadowContent);
     updateLayoutAndStyleForPainting();
 
     RefPtrWillBeRawPtr<Element> host = document().getElementById("host");
 
     EXPECT_EQ(Position::lastPositionInNode(host.get()), Position::afterNode(host.get()).downstream());
     EXPECT_EQ(PositionInComposedTree::lastPositionInNode(host.get()), PositionInComposedTree::afterNode(host.get()).downstream());
 }
 
+// TODO(yoisn) We should move |NextNodeIndex| to "EditingUtilitiesTest.cpp".
 TEST_F(PositionTest, NextNodeIndex)
 {
     const char* bodyContent = "<p id='host'>00<b id='one'>11</b><b id='two'>22</b>33</p>";
     const char* shadowContent = "<content select=#two></content><content select=#one></content>";
     setBodyContent(bodyContent);
     setShadowContent(shadowContent);
     Node* host = document().getElementById("host");
     Node* two = document().getElementById("two");
 
-    EXPECT_EQ(Position(host, 3), Position(two, 2).next());
-    EXPECT_EQ(PositionInComposedTree(host, 1), PositionInComposedTree(two, 2).next());
+    EXPECT_EQ(Position(host, 3), nextPositionOf(Position(two, 2), PositionMoveType::CodePoint));
+    EXPECT_EQ(PositionInComposedTree(host, 1), nextPositionOf(PositionInComposedTree(two, 2), PositionMoveType::CodePoint));
 }
 
 TEST_F(PositionTest, NodeAsRangeLastNodeNull)
 {
     EXPECT_EQ(nullptr, Position().nodeAsRangeLastNode());
     EXPECT_EQ(nullptr, PositionInComposedTree().nodeAsRangeLastNode());
 }
 
 TEST_F(PositionTest, NodeAsRangeLastNode)
 {
@@ skipping 120 matching lines @@
 
     RefPtrWillBeRawPtr<Element> host = document().getElementById("host");
     RefPtrWillBeRawPtr<Element> one = document().getElementById("one");
     RefPtrWillBeRawPtr<Element> three = shadowRoot->getElementById("three");
 
     EXPECT_EQ(Position(one->firstChild(), 1), Position::afterNode(host.get()).upstream());
     EXPECT_EQ(PositionInComposedTree(three->firstChild(), 3), PositionInComposedTree::afterNode(host.get()).upstream());
 }
 
 } // namespace blink